Let’s assume for the moment that you have the backing of a major film studio. Got that? Good. Now, turning a cartoon strip into a CGI film seems like one of the easier filmmaking tasks — the characters have been designed and the film is already storyboarded. You can just sit back and let the animators fill in the gaps. Right?
Not quite, it turns out. These shots depicting the making of Steven Spielberg’s upcoming blockbuster The Adventures Of Tintin: The Secret Of The Unicorn suggest just how tough it can be.
The move from Hergé’s original work  to concept art  is the simplest — it was a chance for the artists at effects studio Weta to bring their favourite scenes closer to reality. But where do you go from there?
Live-action was discussed, but when motion-capture  was agreed on, the look of Tintin (played by Jamie Bell) was the trickiest proposition. “Human faces have muscle structure, wrinkles and so on,” explains Weta’s Marco Revelant. “The original face ended up smooth like a ball without these essential characteristics. When we started adding them, it no longer looked like the graphic.” Put simply, you lose the instant recognition that such an iconic character should have.
Eventually, having solved how the characters should appear, the film can be made. The final shot in the sequence  is originally from Red Rackham’s Treasure, one of the three books that have been adapted for the film (with The Secret Of The Unicorn and The Crab With The Golden Claws).
Notice the difference between the stormy seas of the artwork and the relative calmness of the finished film? That was borne out of making Tintin exist in the “real world” — as Weta’s Keith Miller accepts, if they depicted the water as being as turbulent as shown in the original panel, “the seaplane wouldn’t be able to take off”.
So, clearly it’s not as easy as we thought. In fact, we may now rank it second trickiest — after working with a cast consisting of children, animals and a seriously ticked-off Christian Bale.
The Art Of The Adventures Of Tintin is out now, priced £25